Oral pretreatment with recombinant human lactoferrin limits trauma-hemorrhagic shock–induced gut injury and the biological activity of mesenteric lymph

Background

Lactoferrin (LF) is a pleiotropic glycoprotein that is found in bodily secretions and is postulated to enhance the gastrointestinal barrier and promote mucosal immunity. Thus, the ability of talactoferrin, an oral recombinant form of human LF, to limit gut injury and the production of biologically active gut-derived products was tested using a rat model of trauma–hemorrhagic shock (T/HS).

Methods

Male rats were orally dosed with vehicle or talactoferrin (1000 mg/kg, every day) for 5 d before being subjected to T/HS or trauma–sham shock (T/SS). Subsequently, rats were subjected to a laparotomy (trauma) and hemorrhagic shock (mean arterial pressure, 30–35 mm Hg × 90 min) or to T/SS, followed by resuscitation with their shed blood. Before inducing shock, the mesenteric lymphatic duct was catheterized for collection of mesenteric lymph. Four hours after the end of the shock or sham-shock period, rats were sacrificed, a segment of the distal ileum was collected for morphologic analysis, and lymph samples were processed and frozen. Subsequently, lymph samples were tested in several pharmacodynamic assays, including endothelial cell permeability, neutrophil respiratory burst activity, and red blood cell (RBC) deformability. Total white blood cell counts in lymph samples were also quantified.

Results

Pretreatment with talactoferrin reduced the incidence of T/HS-induced morphologic injury of ileum to T/SS levels. Post-T/HS lymph from vehicle-treated rats increased endothelial monolayer permeability and neutrophil priming for an augmented respiratory burst, and induced loss of RBC deformability, compared with T/SS groups. Talactoferrin pretreatment significantly reduced the biological activity of T/HS lymph on respiratory burst activity and RBC deformability, but had no effect on the lymph cell count or endothelial cell permeability.

Conclusions

These results provide a proof of principle that prophylactic dosing of oral talactoferrin can potentially protect the gut in a T/HS model and limit the production of biologically active factors in rat gastrointestinal tissue subjected to ischemia-reperfusion–type injuries.     

Gene expression in fetal murine keratinocytes and fibroblasts

Background

Early fetuses heal wounds without the formation of a scar. Many studies have attempted to explain this remarkable phenomenon. However, the exact mechanism remains unknown. Herein, we examine the predominant cell types of the epidermis and dermis—the keratinocyte and fibroblast—during different stages of fetal development to better understand the changes that lead to scarring wound repair versus regeneration.

Materials and methods

Keratinocytes and fibroblasts were harvested and cultured from the dorsal skin of time-dated BALB/c fetuses. Total RNA was isolated and microarray analysis was performed using chips with 42,000 genes. Significance analysis of microarrays was used to select genes with >2-fold expression differences with a false discovery rate <2. Enrichment analysis was performed on significant genes to identify differentially expressed pathways.

Results

By comparing the gene expression profile of keratinocytes from E16 versus E18 fetuses, we identified 24 genes that were downregulated at E16. Analysis of E16 and E18 fibroblasts revealed 522 differentially expressed genes. Enrichment analysis showed the top 20 signaling pathways that were downregulated in E16 keratinocytes and upregulated or downregulated in E16 fibroblasts.

Conclusions

Our data reveal 546 differentially expressed genes in keratinocytes and fibroblasts between the scarless and scarring transition. In addition, a total of 60 signaling pathways have been identified to be either upregulated or downregulated in these cell types. The genes and pathways recognized by our study may prove to be essential targets that may discriminate between fetal wound regeneration and adult wound repair.     

Association of Intraprocedural Blood Pressure and End Tidal Carbon Dioxide with Outcome After Acute Stroke Intervention

Background

General anesthesia (GA) for acute stroke interventions may be associated with inferior functional outcomes. Our goal was to identify physiologic parameters that mediate this association.

Methods

Consecutive patients treated at our institution between August 2007 and December 2010 were identified from a prospective database. Clinical data were then extracted by retrospective chart review. Variables significantly associated with outcome in univariate analysis were also examined in multivariate analysis, controlling for well-established prespecified predictors of functional outcome.

Results

Of the 106 patients identified, 20 were excluded (17 due to the absence of 90-day mRS and 3 due to insufficient anesthetic records). Blood pressure (BP) decreased significantly after induction of GA, but there was no association between BP and outcome. End tidal carbon dioxide values (ETCO2) at 60 and 90 min, however, were significantly associated with outcomes in both univariate and multivariate analyses. Mean ETCO2 in patients with favorable outcomes (modified Rankin Scale (mRS) 0–3) was higher than in those with unfavorable outcomes (mRS 4–6): 35.2 mmHg versus 32.2 (p = 0.03) at 60 min and 34.9 versus 31.9 (p = 0.04) at 90 min. The adjusted odds ratios for poor outcomes for each 1 mmHg decrease in ETCO2 were the same: 0.76 (95 % CI 0.65–0.92; p = 0.004) at 60 min and 0.76 (95 % CI 0.61–0.93; p = 0.01) at 90 min.

Conclusions

While BP decreased significantly in patients undergoing GA for acute stroke intervention, it did not correlate with patient outcome. Decreases in ETCO2 at 30 and 60 min, however, were associated with 90-day mRS.